My earlier U.S. Pat. No. 3,139,286 issued June 30, 1964 and titled "Tank Truck Hopper Body Formed with Arcuate Surfaces" discusses at length the attributes of having an enclosed tank body of the aforementioned type characterized by the formation of the enclosing walls thereof by the intersection and interconnection of a series of arcuate surfaces. One primary advantage of such an arrangement is that in lieu of heavy gauge flat plates inclined at the necessary angle for unloading of the free-falling product, lighter gauge metals formed for the proper arcuate configuration may be employed because such arcuate configuration better distributes the stresses due to internal forces, thereby permitting the overall weight of the tank body to be considerably lighter than prior constructions per cubic foot of volume.
Thus, from my aforesaid earlier patent, the attributes of a properly arcuately formed hopper body have become well known and accepted in the art, and yet, even those tank bodies constructed in accordance with the teachings of my aforesaid patent have been limited insofar as their carrying capacity is concerned as a result of the angle selected for the slope sheet of the tank body along the longitudinal axis thereof.